Gate valves and globe valves can be used as a cut-off medium in pipelines because of their similar appearance. So for some newcomers entering the valve industry or those who have little knowledge of valves, the difference between the two will be indistinguishable. What is the difference between a gate valve and a globe valve with a seemingly identical appearance? After collecting and sorting out the small valves of Bundor, Bundor listed the following differences between the valve and the cut-off valve, hoping to help everyone.
Difference between gate valve and globe valve
1 Structural differences
The structure of the gate valve is more complex than that of the stop valve. First of all, according to the structure, the gate valve is classified into ring stem gate valve and non ring stem gate valve, but the globe valve does not. Second, in terms of appearance, the length of the gate valve is shorter than the globe valve, but its height is higher than the globe valve. Therefore, the gate valve requires more installation space, especially the light valve.
2 Principle difference
The operation method of the gate valve and the globe valve is similar, all of them are turning the hand wheel. The valve stem drives the valve plate to move up and down to achieve the control of the flow. The difference between the two is that the gate valve can only be fully opened and fully closed. When the gate is opened or closed, the stroke is larger and the opening and closing time is longer. The distance between the stop valve plate and the sealing surface is short, the stroke of the valve plate is small, and the valve plate of the stop valve can be stopped at a certain position during the movement to do flow adjustment. This is not available in gate valves. In addition, when the gate valve is installed in the pipeline, there is no requirement for the direction of the entrance and exit, and the medium can flow in both directions. The cut-off valve is stipulated in the direction of the import and export, China's valve "three to give" has given the flow direction of the cut-off valve, shall be adopted from top to bottom.
3 Differences in flow resistance
Because the gate valve can only be fully opened and closed, when it is in the fully open state, the flow path in the entire pipeline is straight. When the fluid medium flows through the valve body channel, there is no blockage, and the flow resistance is almost zero. The cut-off valve, when the medium flows through the valve body channel, the flow direction is from top to bottom, and the resistance of the valve plate is larger.
4 Maintenance and inspection difference
When the gate valve is doing maintenance and inspection, the gate valve needs to be disassembled from the pipeline, and the cost of maintenance and repair is relatively large. The cut-off valve, in most cases, its valve seat and valve can be directly online replacement, do not have to disassemble the entire valve, so when used as a globe valve, globe valve is suitable for the welding of valves and pipelines in one place.